Oil supply device and vehicle drive transmission device

ABSTRACT

An oil supply device has: a first hydraulic pump driven by power transmitted through a power transmission path; a second hydraulic pump driven by a second driving force source independent from the power transmission path; a first supply oil passage that supplies oil discharged by the first hydraulic pump to a lubrication required part of a transmission; and a second supply oil passage that supplies oil discharged by the second hydraulic pump to a hydraulic drive portion of a specific engagement device.

TECHNICAL FIELD

Aspects of the preferred embodiments relate to an oil supply device thatsupplies oil to a transmission, and a vehicle drive transmission devicethat is provided with such an oil supply device.

BACKGROUND ART

An example of the oil supply device described above is disclosed inJapanese Unexamined Patent Application Publication No. 2011-226527 (JP2011-226527 A) (Patent Document 1). The reference symbols shown inparentheses in the description of the background art are those of PatentDocument 1. In the oil supply device of Patent Document 1, set as an oilsupply target is a transmission unit (3) having a configuration in whicha second speed (high shift speed) is formed by having hydraulic pressuresupplied to a first speed clutch (17) and a second speed brake (18) anda first speed (low shift speed) is formed when the supply of hydraulicpressure to the first speed clutch (17) and the second speed brake (18)is stopped from a state in which the second speed is formed. The oilsupply device of Patent Document 1 includes an oil pump (8) driven bypower transmitted through a power transmission path between a travelingdrive motor (2) and left and right drive wheels (1L, 1R), and isconfigured to supply oil discharged from the oil pump (8) to the firstspeed clutch (17), the second speed brake (18), and a lubricationrequired part.

RELATED ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2011-226527 (JP 2011-226527 A)

SUMMARY Problem to be Solved

There are cases in which it is desired to maintain a state in which oneshift speed is formed until a vehicle stops, in order to suppresschanges in vehicle behavior to a small extent. Regarding this point, inthe oil supply device according to Patent Document 1, since thehydraulic pump is driven by power transmitted through the powertransmission path, when the vehicle is caused to stop in the state inwhich the high shift speed is formed, it is not possible to maintain thestate in which the high shift speed is formed until the vehicle isstopped, for example. Thus, maintaining the state is considered in whichone shift speed is formed until the vehicle is stopped, by using ahydraulic pump that is driven by a driving force source independent fromthe power transmission path instead of the hydraulic pump driven bypower transmitted through the power transmission path. However, in theoil supply device according to Patent Document 1, both the hydraulicpressure needed for engagement operation of an engagement device(specifically, the first speed clutch and the second speed clutch) andan oil amount needed to lubricate each portion are ensured by drivingone hydraulic pump. Thus, a discharge capacity required for thehydraulic pump tends to be large, which may lead to an increase in costand a decrease in efficiency when using the hydraulic pump driven by thedriving force source independent from the power transmission pathinstead of the hydraulic pump driven by power transmitted through thepower transmission path.

Therefore, a technique in which a decrease in cost and an increase inefficiency can be achieved when using the hydraulic pump driven by thedriving force source independent from the power transmission path isdesired.

Means for Solving the Problem

In view of the description above, the characteristic configuration of anoil supply device that supplies oil to a transmission provided in apower transmission path connecting a rotating electrical machine andwheels is as follows. The transmission is configured to form differentshift speeds based on whether hydraulic pressure is supplied to aspecific engagement device. The oil supply device includes: a firsthydraulic pump driven by power transmitted through the powertransmission path; a second hydraulic pump driven by a driving forcesource independent from the power transmission path; a first supply oilpassage that supplies oil discharged by the first hydraulic pump to alubrication required part of the transmission; and a second supply oilpassage that supplies oil discharged by the second hydraulic pump to ahydraulic drive portion of the specific engagement device.

According to the configuration described above, oil discharged by thesecond hydraulic pump driven by the driving force source independentfrom the power transmission path can be supplied to the hydraulic driveportion of the specific engagement device via the second supply oilpassage. Thus, by continuing to drive the second hydraulic pump when thevehicle is caused to stop in the state in which hydraulic pressure issupplied from the second hydraulic pump to the specific engagementdevice so that one shift speed is formed, it is possible to maintain thestate in which the shift speed is formed until the vehicle is stopped.According to the configuration described above, besides the secondhydraulic pump, the first hydraulic pump driven by power transmittedthrough the power transmission path is provided, and oil discharged bythe first hydraulic pump can be supplied to the lubrication requiredpart of the transmission via the first supply oil passage. Thus,compared to when oil discharged by the second hydraulic pump is suppliedto the lubrication required part of the transmission, it is possible tosuppress the discharged capacity required for the second hydraulic pump(specifically, the maximum value of the required discharge amount) to besmall. In this way, the cost can be reduced and the efficiency can beimproved. In terms of the first hydraulic pump, since oil discharged bythe second hydraulic pump can be supplied to the hydraulic drive portionof the specific engagement device, the discharged capacity required forthe first hydraulic pump (specifically, the maximum required dischargepressure) can be suppressed to be small. In this way, it is possible toreduce the energy loss that occurs in conjunction with the firsthydraulic pump being driven and improve the efficiency. As describedabove, according to the configuration described above, it is possible toreduce the cost and improve the efficiency when using the hydraulic pumpdriven by the driving force source independent from the powertransmission path. According to the configuration described above, sincethe discharge capacities of both the first hydraulic pump and the secondhydraulic pump can be suppressed to be small, there is the advantage ofbeing able to reduce the size of the two hydraulic pumps.

Further features and advantages of the oil supply device will beapparent from the following description of the embodiments which isgiven with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a skeleton diagram of a vehicle drive transmission deviceaccording to an embodiment.

FIG. 2 is a speed diagram of a differential gear device according to theembodiment.

FIG. 3 is an operation table of a transmission according to theembodiment.

FIG. 4 is a schematic diagram of an oil supply device according to theembodiment.

FIG. 5 is a diagram of an oil flow in a first state of the oil supplydevice according to the embodiment.

FIG. 6 is shows an oil flow in a second state of the oil supply deviceaccording to the embodiment.

FIG. 7 is a skeleton diagram of a vehicle drive transmission deviceaccording to another embodiment.

FIG. 8 is a speed diagram of a differential gear device according to theother embodiment.

BEST MODE

Embodiments of an oil supply device and a vehicle drive transmissiondevice will be described with reference to the drawings.

In the following description, the term “drivingly coupled” refers to astate in which two rotating elements are coupled so as to be able totransmit a driving force (same meaning as a torque), and the stateincludes a state in which the two rotating elements are coupled so as torotate integrally or a state in which the two rotating elements arecoupled to be able to transmit the driving force via one or two or moretransmission members. Examples of such a transmission member includevarious types of members that transmit rotation at the same speed or ata shifted speed, such as a shaft, a gear mechanism, a belt, and a chain.The transmission member may include an engagement device thatselectively transmits a rotation and a driving force, such as a frictionengagement device or a meshing engagement device. However, when eachrotating element of a differential gear device or a planetary gearmechanism is “drivingly coupled”, this indicates a state in which threeor more rotating elements provided in the differential gear device orthe planetary gear mechanism are drivingly coupled without interposingother rotating elements.

In addition, the term “rotating electrical machine” is used as a conceptincluding all of a motor (electric motor), a generator (electricgenerator), and a motor generator that functions as both a motor and agenerator as necessary.

As illustrated in FIG. 1, an oil supply device 7 is a device thatsupplies oil to a transmission 6 provided on a power transmission paththat connects a first driving force source M1 (a rotating electricalmachine 10, as described below) and wheels 2. The oil supply device 7sets as an oil supply target, the transmission 6 that is configured suchthat different shift speeds are formed depending on whether hydraulicpressure is supplied to a specific engagement device D. In the presentembodiment, the oil supply device 7 sets as the oil supply target, thetransmission 6 that is configured such that a first forward speed isformed by supplying hydraulic pressure to the specific engagement deviceD, and a second forward speed having a larger speed ratio than that ofthe first forward speed is formed when supply of the hydraulic pressureto the specific engagement device D is stopped after the first forwardspeed is formed. The oil supply device 7 is provided in the vehicledrive transmission device 1 together with the transmission 6. Below, theconfiguration of the vehicle drive transmission device 1 will bedescribed, and then the configuration of the oil supply device 7provided in the vehicle drive transmission device 1 will be described.

As illustrated in FIG. 1, the vehicle drive transmission device 1 hasthe oil supply device 7, the transmission 6, and an output member 3drivingly coupled to the wheels 2. The transmission 6 is provided in thepower transmission path between the first driving force source M1 andthe output member 3. The vehicle drive transmission device 1 is furtherprovided with a case 4 that houses the transmission 6. The output member3 is also housed in the case 4. The vehicle drive transmission device 1is configured to be able to transmit the driving force of the firstdriving force source M1 to the output member 3. That is, the vehicledrive transmission device 1 is a device for transmitting the drivingforce of the first driving force source M1 to the output member 3 andmaking a vehicle (a vehicle in which the vehicle drive transmissiondevice 1 is installed) travel. In the present embodiment, the case 4corresponds to a “non-rotating member”.

The first driving force source M1 is a driving force source of thewheels 2. The first driving force source M1 is the rotating electricalmachine 10 and the vehicle drive transmission device 1 is configuredsuch that the torque of the rotating electrical machine 10 istransmitted to the output member 3.

In the present embodiment, the vehicle drive transmission device 1includes an output differential gear device 5 in a power transmissionpath between the output member 3 and the two left and right wheels 2.The output differential gear device 5 is housed in the case 4. Theoutput differential gear device 5 is provided with a differential inputgear 5 a that meshes with an output gear 3 a provided in the outputmember 3, and distributes the torque input from the output member 3 tothe differential input gear 5 a to the two left and right wheels 2. Theconfiguration may be such that a counter gear mechanism is provided inthe power transmission path between the output member 3 and the outputdifferential gear device 5, and the torque is input from the outputmember 3 to the output differential gear device 5 via the counter gearmechanism. Further, in the present embodiment, the configuration is suchthat the first driving force source M1 is drivingly coupled to the twoleft and right wheels 2 (that is, the configuration is such that thefirst driving force source M1 is the driving force source of the twowheels 2). However, the configuration may be such that the vehicle drivetransmission device 1 does not have the output differential gear device5 and that the first driving force source M1 is drivingly coupled toonly one of the two wheels 2 (that is, the configuration may be suchthat the vehicle drive transmission device 1 transmits the driving forceof the first driving force source M1 to only one of the two left andright wheels 2 and not the two left and right wheels 2).

The rotating electrical machine 10 is housed in the case 4. The rotatingelectrical machine 10 is provided with a stator 12 fixed to the case 4and a rotor 11 supported so that the rotor 11 is rotatable relative tothe stator 12. The rotating electrical machine 10 is electricallyconnected to an electricity storage device (not shown) such as a batteryor a capacitor device, and performs power running by using electricpower supplied from the electricity storage device or supplies electricpower generated by inertial force of the vehicle etc. to the electricitystorage device so as to store the electric power therein.

As illustrated in FIG. 1, the transmission 6 has a differential geardevice 20. The differential gear device 20 is at least provided with, inan order of rotational speed, a first rotating element E1 that isdrivingly coupled to the rotating electrical machine 10, a secondrotating element E2 that is drivingly coupled to the output member 3,and a third rotating element E3 that is selectively fixed to the case 4by a second engagement device D2. The first rotating element E1 isdrivingly coupled to the rotating electrical machine 10 withoutinterposing another rotating element provided in the differential geardevice 20. The second rotating element E2 is drivingly coupled to theoutput member 3 without interposing another rotating element provided inthe differential gear device 20.

Here, the term “an order of rotational speed” refers to the order ofrotational speed of each rotational element in the rotational state. Therotational speed of each rotating element changes depending on therotational state of the differential gear device or the planetary gearmechanism. However, the order of the rotational speed of each rotatingelement is determined by the structure of the differential gear deviceor the planetary gear mechanism and is therefore always the same. Theterm “the order of rotational speed of each rotating element” is equalto a disposition order of each rotating element in a speed diagram (seealignment chart, FIG. 2). Here, the term “the disposition order of eachrotating element in a speed diagram” means the order in which an axiscorresponding to each rotating element in the speed diagram (alignmentchart) is disposed along a direction orthogonal to the axis. Althoughthe disposition direction of the axis corresponding to each rotatingelement in the speed diagram (alignment chart) differs depending on howthe speed diagram is drawn, the disposed order is fixed since it isdetermined by the structure of the differential gear device or theplanetary gear mechanism.

In the present embodiment, the differential gear device 20 is configuredof one planetary gear mechanism (first planetary gear mechanism 21), andhas only three rotating elements, which are the first rotating elementE1, the second rotating element E2, and the third rotating element E3.In the present embodiment, the first planetary gear mechanism 21 is asingle-pinion type planetary gear mechanism. Then, in the presentembodiment, a first ring gear 21 r that is a ring gear of the firstplanetary gear mechanism 21 is drivingly coupled to the rotatingelectrical machine 10 and a first carrier 21 c that is a carrier of thefirst planetary gear mechanism 21 is drivingly coupled to the outputmember 3, without interposing another rotating element of the firstplanetary gear mechanism 21. Specifically, the first ring gear 21 r iscoupled to the rotating electrical machine 10 (rotor 11) so that thefirst ring gear 21 r rotates integrally therewith. The first carrier 21c is coupled to a rotating element (specifically, a second sun gear 22s) of a second planetary gear mechanism 22 described below that isprovided in the power transmission path between the first planetary gearmechanism 21 and the output member 3, so that the first carrier 21 crotates integrally with the rotating element of the second planetarygear mechanism 22. Thus, in the present embodiment, the first ring gear21 r is the first rotating element E1, the first carrier 21 c is thesecond rotating element E2, and a first sun gear 21 s is the thirdrotating element E3. A configuration in which the first sun gear 21 s isthe first rotating element E1 and the first ring gear 21 r is the thirdrotating element E3 is also possible. Also, a double pinion typeplanetary gear mechanism can be used as the first planetary gearmechanism 21.

In the present embodiment, the transmission 6 has the second planetarygear mechanism 22 in the power transmission path between thedifferential gear device 20 and the output member 3. The secondplanetary gear mechanism 22 is configured to reduce the speed of therotation input from the first planetary gear mechanism 21 at a speedratio corresponding to the gear ratio of the second planetary gearmechanism 22 and transmit the resultant rotation to the output member 3.Specifically, the second planetary gear mechanism 22 is a single piniontype planetary gear mechanism. The second sun gear 22 s that is the sungear of the second planetary gear mechanism 22 is coupled to the firstcarrier 21 c so that the second sun gear 22 s rotates integrally. Asecond carrier 22 c that is a carrier of the second planetary gearmechanism 22 is coupled to the output member 3 so that the secondcarrier 22 c rotates integrally. A second ring gear 22 r that is a ringgear of the second planetary gear mechanism 22 is fixed to the case 4.The configuration may be such that the transmission 6 is not providedwith the second planetary gear mechanism 22 and the second rotatingelement E2 of the differential gear device 20 is coupled to the outputmember 3 so that the second rotating element E2 rotates integrally.

As illustrated in FIG. 1, in the present embodiment, the rotatingelectrical machine 10, the output member 3, and the transmission 6 aredisposed coaxially (here, on a first axis A1). In contrast, the outputdifferential gear device 5 is disposed on a second axis A2 that isparallel with the first axis A1 and that is different from the firstaxis A1. Here, the first axis A1 and the second axis A2 are virtualaxes. In the present embodiment, the second planetary gear mechanism 22is disposed between the differential gear device 20 (first planetarygear mechanism 21) and the rotating electrical machine 10 in an axialdirection that is based on the first axis A1. The configuration may besuch that the second planetary gear mechanism 22 disposed on theopposite side of the differential gear device 20 (first planetary gearmechanism 21) from the rotating electrical machine 10 side in the axialdirection that is based on the first axis A1.

As described above, in the present embodiment, the transmission 6 isconfigured such that the first forward speed is formed by supplyinghydraulic pressure to the specific engagement device D, and the secondforward speed having a larger speed ratio than that of the first forwardspeed is formed when supply of the hydraulic pressure to the specificengagement device D is stopped after the first forward speed is formed.In the present embodiment, the transmission 6 is provided with the firstengagement device D1 and the second engagement device D2 that are twospecific engagement devices D. As described above, the second engagementdevice D2 is an engagement device that selectively fixes the thirdrotating element E3 of the differential gear device 20 to the case 4. Inthe present embodiment, the first engagement device D1 is a clutch Cthat selectively couples two rotating elements among the first rotatingelement E1, the second rotating element E2, and the third rotatingelement E3. That is, two rotating elements among the first rotatingelement E1, the second rotating element E2, and the third rotatingelement E3 are coupled by first engagement device D1 in an engagementstate (an engaged state; the same applies hereinafter). The firstrotating element E1 is drivingly coupled to the rotating electricalmachine 10 without interposing the first engagement device D1, and thesecond rotating element E2 is drivingly coupled to the output member 3without interposing the first engagement device D1.

The clutch C is a normally open type engagement device, and isconfigured to be engaged when the hydraulic pressure is supplied andreleased when supply of the operating hydraulic pressure is stopped.That is, in the first engagement device D1 (clutch C), hydraulicpressure is supplied to a first hydraulic drive portion 71 (see FIG. 4)that is a hydraulic drive portion 70 (such as a hydraulic servomechanism etc.) of the first engagement device D1 so that the firstengagement device D1 is switched to the engagement state. The firstengagement device D1 (clutch C) is switched to the released state by thesupply of hydraulic pressure to the first hydraulic drive portion 71being stopped. In the present embodiment, the clutch C is provided so asto couple the second rotating element E2 and the third rotating elementE3 when the clutch C is in the engagement state. In the presentembodiment, a friction engagement device is used as the clutch C.

The second engagement device D2 is configured so as to at least be ableto be switched between a one-direction restriction state in whichrotation of the third rotating element E3 is restricted to one directionand a rotation restriction state in which rotation of the third rotatingelement E3 is restricted in both directions. That is, in the presentembodiment, the second engagement device D2 is a one-way clutch F(selectable one-way clutch). The second engagement device D2 (one-wayclutch F) is switched to the one-direction restriction state by havinghydraulic pressure supplied to a second hydraulic drive portion 72 (seeFIG. 4) that is the hydraulic drive portion 70 of the second engagementdevice D2. The second engagement device D2 (one-way clutch F) isswitched to the rotation restriction state by having the supply ofhydraulic pressure to the second hydraulic drive portion 72 stopped. Inthis specification, a clutch configured using a two-way clutch(selectable two way clutch) is also called a one way clutch. Here, thetwo-way clutch is able to switch between another direction restrictionstate in which rotation in another one direction of the third rotatingelement is restricted and a restriction disabled state in which rotationof the third rotating element E3 is allowed in both directions, inaddition to the one-direction restriction state and the rotationrestriction state.

A first reaction force torque TR1 is defined as a reaction force torquethat is applied to the third rotating element E3 when the rotatingelectrical machine 10 outputs a normal rotation torque T1 in a forwardpower running direction, and a second reaction force torque TR2 isdefined as a reaction force torque that is applied to the third rotatingelement E3 when the rotating electrical machine 10 outputs a reverserotation torque T2 that is in a direction opposite to the normalrotation torque T1 is (see FIG. 2). In this case, in the one-directionrestriction state, the one-way clutch F is configured to restrictrotation of the third rotating element E3 in the rotation directioncaused by the first reaction force torque TR1 and allow rotation of thethird rotating element E3 in the rotation direction caused by the secondreaction force torque TR2. That is, the one-way clutch F is engaged bythe first reaction force torque TR1 applied to the third rotatingelement E3 and released by the second reaction force torque TR2 appliedto the third rotating element E3, in the one-direction restrictionstate. Thus, rotation of the third rotating element E3 in one direction(rotation in the rotation direction due to the first reaction forcetorque TR1) is restricted. That is, with the rotation direction of thesecond rotating element E2 set as the positive direction while thevehicle is travelling forward, the one-way clutch F restricts rotationof the third rotating element E3 in a negative direction and allowsrotation of the third rotating element E3 in the positive direction, inthe one-direction restriction state. Further, in the rotationrestriction state, the one-way clutch F restricts rotation (rotation inthe negative direction) of the third rotating element E3 in the rotationdirection caused by the first reaction force torque TR1 and alsorestricts rotation (rotation in the positive direction) of the thirdrotating element E3 in the rotation direction caused by the secondreaction force torque TR2.

As the one-way clutch F configured as described above, a combination ofa first one way clutch and a second one way clutch that are two one wayclutches can be used, for example. Here, the first one-way clutch isconfigured so as to be able to switch between a restriction effectivestate in which rotation of the third rotating element E3 in the positivedirection is restricted and rotation of the third rotating element inthe negative direction is allowed, and the restriction disabled state inwhich rotation of the third rotating element E3 in both directions isallowed. The second one-way clutch is configured to restrict rotation ofthe third rotating element E3 in the negative direction and allowrotation of the third rotating element E3 in the positive direction.

The transmission 6 has the first engagement device D1 (in the presentembodiment, the clutch C) and the second engagement device D2 (in thepresent embodiment, the one-way clutch F) having the above-describedconfigurations. Thus, as illustrated in FIG. 2, a first forward speedand a second forward speed with a larger speed ratio than that of thefirst forward speed (a ratio of the rotation speed of the first drivingforce source M1 to the rotation speed of the output member 3) can beformed so as to be switchable, as shift speeds for forward travelling inwhich the normal rotation torque T1 of the rotating electrical machine10 is transmitted to the wheels 2 to make the vehicle travel forward. InFIG. 2, the first forward speed that is a higher shift speed among thefirst forward speed and the second forward speed is expressed as “High”,and the second forward speed that is a lower shift speed among the firstforward speed and the second forward speed is expressed as “Low”.Further, the reverse speed in which the reverse rotation torque T2 ofthe rotating electrical machine 10 is transmitted to the wheels 2 sothat the vehicle travels rearward is expressed as “Rev”.

FIG. 3 shows an operation table of the transmission 6. In the operationtable of FIG. 3, for the one-way clutch F, a triangular mark indicatesthe one-direction restriction state and a circle mark indicates therotation restriction state. Further, in the operation table of FIG. 3,for the clutch C, a circle mark indicates the engagement state andunmarked indicates the released state.

As illustrated in FIG. 3, the first forward speed (High) is formed byswitching the clutch C to the engagement state (direct couplingengagement state) and switching the one-way clutch F to theone-direction restriction state. As indicated in FIG. 2, in the firstforward speed (High), all the rotating elements of the first planetarygear mechanism 21 are rotated integrally at the same speed, and rotationinput from the rotating electrical machine 10 side to the first rotatingelement E1 is output from the second rotating element E2 to the outputmember 3 side at the same rotating speed. Further, the second forwardspeed (Low) is formed by switching the clutch C to the released stateand the one-way clutch F to the rotation restriction state. Asillustrated in FIG. 2, in the second forward speed (Low), rotation inputfrom the rotating electrical machine 10 side to the first rotatingelement E1 is decelerated at a speed ratio corresponding to the gearratio of the first planetary gear mechanism 21, and is output from thesecond rotating element E2 to the output member 3 side. During forwardpower running, the second forward speed (Low) can be formed even whenthe one-way clutch F is switched to the one-direction restriction state.However, by switching the one-way clutch F to the rotation restrictionstate, regenerative running at the second forward speed (Low) ispossible. Further, the reverse speed (Rev) is formed by switching theclutch C to the released state and the one-way clutch F to the rotationrestriction state.

As illustrated in FIG. 1, in the present embodiment, the transmission 6has a brake B besides the second engagement device D2 as a device forselectively fixing the third rotating element E3 of the differentialgear device 20 to the case 4. In this way, by engaging the brake B (slipengagement) while releasing the clutch C when switching the shift speedfrom the first forward speed (High) to the second forward speed (Low),the rotation speed of the third rotating element E3 can be reduced. Inparticular, by engaging the brake B, the rotation speed of the thirdrotating element E3 can be reduced even when the second reaction forcetorque TR2 corresponding to the reverse rotation torque T2 of therotating electrical machine 10 is applied to the third rotating elementE3. Thus, it is possible to switch the shift speed from the firstforward speed (High) to the second forward speed (Low) duringregenerative traveling.

In the present embodiment, the brake B is a normally open type brake,and is configured to be engaged when the hydraulic pressure is suppliedand released when supply of the hydraulic pressure is stopped. That is,the brake B is switched to the engagement state by hydraulic pressurebeing supplied to a third hydraulic drive portion 73 (see FIG. 4) thatis a hydraulic drive portion of the brake B. Further, the brake B isswitched to the released state by supply of the hydraulic pressure tothe third hydraulic drive portion 73 being stopped. In the presentembodiment, a band brake having a cylindrical drum and a strip-shapedfriction material serving as an engaging member is used as the brake B.A multi-plate frictional engagement element may be used as the brake B.Further, the configuration may be such that the transmission 6 does nothave the brake B.

As illustrated in FIG. 1, the vehicle drive transmission device 1 has acontrol device 9 that controls an engagement state of the firstengagement device D1 (in the present embodiment, an engagement state ofthe clutch C) and an engagement state of the second engagement device D2(in the present embodiment, a state of the one-way clutch F in whichswitching is performed between the one-direction restriction state andthe rotation restriction state), and an engagement state of the brake B.The control device 9 also controls driving of the first driving forcesource M1 (specifically, the rotating electrical machine 10) and drivingof a second driving force source M2 (see FIG. 4) described below. Thecontrol device 9 has a calculation processing device such as a centralprocessing unit (CPU) as a core member and has a storage device such asa random access memory (RAM) or a read only memory (ROM) that can bereferred to by the calculation processing device. Each function of thecontrol device 9 is realized by software (a program) stored in thestorage device such as the ROM, hardware such as a calculation circuitthat is provided separately, or both of them. The control device 9 maybe configured by a collection of a plurality of pieces of hardware (aplurality of separated pieces of hardware) that can communicate witheach other.

The control device 9 is configured to be able to acquire information(sensor detection information) of detection results of various sensorsprovided in the vehicle. The sensor detection information is, forexample, information of an accelerator operation amount information,information of a vehicle speed, and information of a state of charge oran amount of electricity stored in the electricity storage device thatsupplies electric power to the rotating electrical machine 10. Thecontrol device 9 refers to a control map etc. to determine a targetshift speed to be formed in the transmission 6 and a target torque ofthe rotating electrical machine 10 based on the sensor detectioninformation. Then, the control device 9 controls the engagement state ofeach of the first engagement device D1, the second engagement device D2,and the brake B via the oil supply device 7 so that the determinedtarget shift speed is formed. Further, the control device 9 controls therotating electrical machine 10 so as to output the determined targettorque. Although details are omitted, the control device 9 controlsdriving of the rotating electrical machine 10 by controlling an inverterdevice that converts a direct current voltage of the power storagedevice into an alternating voltage and supplies the alternating voltageto the rotating electrical machine 10.

Next, the configuration of the oil supply device 7 according to thepresent embodiment will be described. As illustrated in FIG. 4, the oilsupply device 7 has a first hydraulic pump 31, a second hydraulic pump32, and a hydraulic circuit 8 that supplies oil discharged from thefirst hydraulic pump 31 or the second hydraulic pump 32 to the hydraulicdrive portion 70 (in the present embodiment, the first hydraulic driveportion 71 and the second hydraulic drive portion 72) of the specificengagement device D. The first hydraulic pump 31 and the secondhydraulic pump 32 each suck oil stored in an oil storage portionprovided in a lower portion of the case 4 or the like to generatehydraulic pressure. An internal gear pump, an external gear pump, a vanepump or the like can be used as the first hydraulic pump 31 and thesecond hydraulic pump 32, for example.

The first hydraulic pump 31 is a pump driven by power transmittedthrough a power transmission path connecting the first driving forcesource M1 and the wheels 2. That is, the first hydraulic pump 31 is aso-called mechanical oil pump, and in FIG. 4, the first hydraulic pump31 is referred to as a mechanical oil pump (MOP). In the presentembodiment, the first hydraulic pump 31 is configured to be driven inconjunction with rotation of the wheels 2. The first hydraulic pump 31is driven in conjunction with rotation of the wheels 2 by being coupledto the output member 3 or the differential input gear 5 a so that thefirst hydraulic pump 31 is non-detachable. In the present embodiment, adischarge capacity of the first hydraulic pump 31 is smaller than thedischarge capacity of the second hydraulic pump 32. A configuration inwhich the discharge capacity of the first hydraulic pump 31 is equal tothe discharge capacity of the second hydraulic pump 32, or aconfiguration in which the discharge capacity of the first hydraulicpump 31 is larger than the discharge capacity of the second hydraulicpump 32 is also possible.

The second hydraulic pump 32 is the second hydraulic pump 32 that isdriven by the second driving force source M2 independent from the powertransmission path connecting the first driving force source M1 and thewheels 2. In the present embodiment, the second driving force source M2is an electric motor. That is, the second hydraulic pump 32 is aso-called electric oil pump, and in FIG. 4, the second hydraulic pump 32is referred to as an electric oil pump (EOP). In the present embodiment,the second driving force source M2 corresponds to the “driving forcesource”.

As illustrated in FIG. 4, oil discharged by the first hydraulic pump 31is supplied to a lubrication target part 30 (indicated as LUBE in FIG.4), which is a lubrication required part, via a first supply oil passageL11. The first supply oil passage L11 is provided with an oil cooler(not shown) that cools the oil and the oil cooled by the oil cooler issupplied to the lubrication target part 30. The lubrication target part30 includes gears, bearings, and the rotating electrical machine 10 etc.that are provided in the vehicle drive transmission device 1, and theseare lubricated and cooled by the oil supplied via the first supply oilpassage L11. The gears and the bearings provided in the transmission 6are included in the lubrication target part 30. That is, the oil supplydevice 7 has the first supply oil passage L11 for supplying oildischarged from the first hydraulic pump 31 to the lubrication targetpart 30 (lubrication required part) of the transmission 6. A requiredhydraulic pressure of the lubrication target part 30 is lower than arequired hydraulic pressure of the hydraulic drive portion 70 (such as aline pressure PL). Thus, the first hydraulic pump 31 is driven to supplythe oil to a hydraulic circuit that has a lower pressure than thehydraulic circuit to which oil discharged from the second hydraulic pump32 is supplied, during a normal state in which failure of the secondhydraulic pump 32 has not occurred. In this way, with the oil supplydevice 7, oil discharged from the first hydraulic pump 31 can besupplied to the lubrication target part 30. Thus, compared to when oildischarged from the second hydraulic pump 32 is supplied to thelubrication target part 30, it is possible to suppress a requireddischarge amount (in particular, the maximum required discharged amount)of the second hydraulic pump 32 to be small. Therefore, cost reductionand efficiency improvement can be achieved, and the size of the secondhydraulic pump 32 can be reduced.

In contrast, the second hydraulic pump 32 is driven to supply the oil tothe hydraulic drive portion 70 of the specific engagement device D.Specifically, the hydraulic circuit 8 has control valves (51, 52), whichcontrol the hydraulic pressure to be supplied to the hydraulic driveportion 70, in the oil passage that connects a second discharge port 32a that is the discharge port of the second hydraulic pump 32 and thehydraulic drive portion 70. In the present embodiment, the hydrauliccircuit 8 has a first control valve 51 that controls the hydraulicpressure supplied to the first hydraulic drive portion 71, in the oilpassage (the oil passage including a second supply oil passage L12 and afirst control oil passage L21) that connects the second discharge port32 a and the first hydraulic drive portion 71. Further, the hydrauliccircuit 8 has a second control valve 52 that controls the hydraulicpressure supplied to the second hydraulic drive portion 72, in the oilpassage (the oil passage including the second supply oil passage L12, amodulator pressure oil passage L9, and a second control oil passage L22)that connects the second discharge port 32 a and the second hydraulicdrive portion 72. As described above, the oil supply device 7 has thesecond supply oil passage L12 that supplies oil discharged from thesecond hydraulic pump 32 to the hydraulic drive portion 70 of thespecific engagement device D. In the oil supply device 7, oil dischargedfrom the second hydraulic pump 32 can be supplied to the hydraulic driveportion 70 of the specific engagement device D. It is thus possible tosuppress the required discharge capacity (in particular, the maximumrequired discharge pressure) of the first hydraulic pump 31 to be small.In this way, energy loss due to the driving of the first hydraulic pump31 can be reduced, efficiency can be improved, and the size of the firsthydraulic pump 31 can be reduced.

The first control valve 51 has an input port 51 a to which oil is inputfrom the second discharge port 32 a side, an output port 51 b that is incommunication with the hydraulic drive portion 70 (first hydraulic driveportion 71), and a drain port 51 c that is in communication with a firstdrain oil passage L31. The second control valve 52 has an input port 52a to which oil is input from the second discharge port 32 a side, anoutput port 52 b in communication with the hydraulic drive portion 70(second hydraulic drive portion 72), and a drain port 52 c that is incommunication with a second drain oil passage L32. The output port 51 bof the first control valve 51 is in communication with the firsthydraulic drive portion 71 via the first control oil passage L21. Theoutput port 52 b of the second control valve 52 is in communication withthe second hydraulic drive portion 72 via the second control oil passageL22.

In the present embodiment, the hydraulic circuit 8 further has a thirdcontrol valve 53 that controls the hydraulic pressure supplied to athird hydraulic drive portion 73, in an oil passage (an oil passageincluding the second supply oil passage L12 and a third control oilpassage L23) that connects the second discharge port 32 a and the thirdhydraulic drive portion 73. The third control valve 53 has an input port53 a to which oil is input from the second discharge port 32 a side, anoutput port 53 b that is in communication with the third hydraulic driveportion 73, and a drain port 53 c that is in communication with a drainoil passage (not shown). The output port 53 b of the third control valve53 is in communication with the third hydraulic drive portion 73 via thethird control oil passage L23.

Oil discharged by the second hydraulic pump 32 is supplied to the secondsupply oil passage L12. The hydraulic pressure in the second supply oilpassage L12 is adjusted to the line pressure PL by a line pressureadjusting valve (not shown). Then, the hydraulic pressure (line pressurePL) of the second supply oil passage L12 is input to the input port 51 aof the first control valve 51 and is also input to the input port 53 aof the third control valve 53. Further, the hydraulic circuit 8 has amodulator valve 40 that reduces the hydraulic pressure (line pressurePL) in the second supply oil passage L12 to generate a modulatorpressure PM. The hydraulic pressure (modulator pressure PM) generated bythe modulator valve 40 is output to the modulator pressure oil passageL9, and the hydraulic pressure of the modulator pressure oil passage L9(modulator pressure PM) is input to the input port 52 a of the secondcontrol valve 52.

The first control valve 51 and the third control valve 53 are linearsolenoid valves that adjust (continuously adjust) the hydraulic pressuresupplied to a downstream side according to an applied current. The firstcontrol valve 51 adjusts the hydraulic pressure input to the input port51 a according to the applied current and supplies the adjustedhydraulic pressure to the first hydraulic drive portion 71. The thirdcontrol valve 53 adjusts the hydraulic pressure supplied to the inputport 53 a according to the applied current and supplies the adjustedhydraulic pressure to the third hydraulic drive portion 73. The firstcontrol valve 51 and the third control valve 53 are normally closed-typelinear solenoid valves that close when not energized. That is, when thefirst control valve 51 is not energized, the output port 51 b and thedrain port 51 c are in communication with each other and the hydraulicpressure input to the input port 51 a is shut off. When the thirdcontrol valve 53 is not energized, the output port 53 b and the drainport 53 c are in communication with each other and the hydraulicpressure input to the input port 53 a is cut off.

The second control valve 52 is a switching valve that can switch acommunication state between the ports according to the input hydraulicpressure (signal pressure PS). Specifically, the second control valve 52is provided with a signal pressure input port 52 d in addition to theinput port 52 a, the output port 52 b, and the drain port 52 c. Thestate of the second control valve 52 is switched to a state in which theinput port 52 a and the output port 52 b are in communication with eachother and communication between the output port 52 b and the drain port52 c is blocked, when the signal pressure PS is input to the signalpressure input port 52 d (the state shown in FIG. 5). Further, the stateof the second control valve 52 is switched to a state in whichcommunication between the input port 52 a and output port 52 b isblocked and the output port 52 b and the drain port 52 c are incommunication, when no signal pressure PS is input to the signalpressure input port 52 d (states shown in FIG. 4 and FIG. 6). In FIG. 4to FIG. 6, for the second control valve 52 and a first switching valve41 and a second switching valve 42 described below, a spool (valveelement) sliding inside the sleeve is divided into two and two statesare indicated and the spools are indicated as hatched in the state ofeach drawing.

The hydraulic circuit 8 is provided with a fourth control valve 54 thatgenerates the signal pressure PS input to the signal pressure input port52 d of the second control valve 52. Specifically, the fourth controlvalve 54 uses the hydraulic pressure (in the present embodiment, themodulator pressure PM) input from the second discharge port 32 a side toan input port 54 a provided in the fourth control valve 54 as a sourcepressure to generate the signal pressure PS. The signal pressure PSgenerated by the fourth control valve 54 is output from an output port54 b of the fourth control valve 54 to a signal pressure oil passage L8,and the hydraulic pressure (signal pressure PS) of the signal pressureoil passage L8 is input to the signal pressure input port 52 d of thesecond control valve 52.

The fourth control valve 54 is an on/off solenoid valve that adjusts thepresence or absence of hydraulic pressure supply to the downstream side(switches the presence or absence of hydraulic pressure supply)according to the applied current. That is, the fourth control valve 54switches whether to output the signal pressure PS to the signal pressureoil passage L8 in accordance with the applied current. The fourthcontrol valve 54 is a normally closed solenoid valve that closes whennot energized. That is, the state of the fourth control valve 54 isswitched to a state in which the input port 54 a and the output port 54b are in communication with each other when energized, and is switchedto a state in which communication between the input port 54 a and theoutput port 54 b is blocked when not energized. Thus, when the fourthcontrol valve 54 is energized, the signal pressure PS (the hydraulicpressure approximately the same as the modulator pressure PM) is outputto the signal pressure oil passage L8, and when the fourth control valve54 is not energized, output of the signal pressure PS to the signalpressure oil passage L8 is stopped.

The control device 9 controls the supply state of electric power(energized state) to each of the first control valve 51, the thirdcontrol valve 53, and the fourth control valve 54, thereby switching theshift speed formed in the transmission 6. As described above, the secondforward speed (Low) and the reverse speed (Rev) are formed by switchingthe clutch C to the released state and the one-way clutch F to therotation restriction state. Then, the clutch C is switched to thereleased state by stopping supply of the hydraulic pressure to the firsthydraulic drive portion 71, and the one-way clutch F is switched to therotation restriction state by stopping supply of the hydraulic pressureto the second hydraulic drive portion 72. Thus, as illustrated in FIG.4, when the second forward speed (Low) and the reverse speed (Rev) areformed, there is no need to supply hydraulic pressure to the firsthydraulic drive portion 71, the second hydraulic drive portion 72, andthe third hydraulic drive portion 73 and the second hydraulic pump 32 istherefore stopped. In FIG. 4, the oil passage through which the oilflows while the second forward speed (Low) and the reverse speed (Rev)are formed is emphasized (the line segment is thicker than the other oilpassages). Similarly in FIG. 5 and FIG. 6, the oil passages throughwhich the oil flows are emphasized in the states shown in each drawing.

As described above, the first forward speed (High) is formed byswitching the clutch C to the engagement state and the one-way clutch Fto the one-direction restriction state. The clutch C is switched to theengagement state by supplying hydraulic pressure to the first hydraulicdrive portion 71, and the one-way clutch F is switched to theone-direction restriction state by supplying hydraulic pressure to thesecond hydraulic drive portion 72. Thus, as illustrated in FIG. 5, whenforming the first forward speed (High), it is necessary to supplyhydraulic pressure to the first hydraulic drive portion 71 and thesecond hydraulic drive portion 72, and the second hydraulic pump 32 isdriven and oil discharged from the second hydraulic pump 32 is suppliedto the first hydraulic drive portion 71 and the second hydraulic driveportion 72. Here, since the first control valve 51 is energized, thehydraulic pressure (for example, the line pressure PL) adjusted by thefirst control valve 51 with the line pressure PL as the source pressureis supplied to the first hydraulic drive portion 71 as a hydraulicpressure. Further, due to the fourth control valve 54 being energizedand the signal pressure PS being input to the signal pressure input port52 d of the second control valve 52, the input port 52 a and the outputport 52 b of the second control valve 52 are in communication. Thus, themodulator pressure PM is supplied to the second hydraulic drive portion72 as the hydraulic pressure.

When a failure in which the discharge pressure of the second hydraulicpump 32 is reduced occurs (hereinafter simply referred to as a“failure”) in a specific state in which oil discharged from the secondhydraulic pump 32 is supplied to the hydraulic drive portion 70 (in thepresent embodiment, the first hydraulic drive portion 71 and the secondhydraulic drive portion 72) so that the first forward speed (High) isformed, there is a possibility that supply of the hydraulic pressure tothe first hydraulic drive portion 71 and the second hydraulic driveportion 72 is stopped and the second forward speed (Low) is forciblyformed. Such a failure may occur due to an abnormality in the secondhydraulic pump 32, power supply to the oil supply device 7 beingblocked, or the like. In view of this point, in the oil supply device 7,the configuration is such that when a failure occurs in the specificstate, the state of the hydraulic circuit 8 is switched from a firstsupply state in which oil discharged from the second hydraulic pump 32is supplied to the hydraulic drive portion 70 (the state shown in FIG.5) to a second supply state (the state shown in FIG. 6) in which oildischarged from the first hydraulic pump 31 is supplied to the hydraulicdrive portion 70. Then, in the present embodiment, the configuration issuch that in the second supply state, the state in which the firstforward speed is formed is maintained by oil discharged from the firsthydraulic pump 31. In this way, when a failure occurs in the specificstate, a state in which the first forward speed (High) is formed can bemaintained by supplying the oil to the hydraulic drive portion 70 fromthe first hydraulic pump 31 instead of the second hydraulic pump 32. Theconfiguration of the hydraulic circuit 8 of the present embodiment forrealizing such a configuration will be described below.

As illustrated in FIG. 4, the hydraulic circuit 8 is provided with thefirst switching valve 41 in an oil passage that connects the hydraulicdrive portion 70 and the first discharge port 31 a that is a dischargeport of the first hydraulic pump 31 (the oil passage including a firstoil passage L1, a second oil passage L2, and a third oil passage L3).The first switching valve 41 is configured to be able to switch betweena first allowing state (a state shown in FIG. 6) in which the oil isallowed to flow from the first discharge port 31 a side to the hydraulicdrive portion 70 side and a first blocked state (a state shown in FIG. 4and FIG. 5) in which the oil is blocked from flowing from the firstdischarge port 31 a side to the hydraulic drive portion 70 side.

Specifically, the first switching valve 41 is provided with a firstinput port 41 a and a second input port 41 b to which oil is input fromthe first discharge port 31 a side, an output port 41 c that outputs theoil to the hydraulic drive portion 70 side, and a signal pressure inputport 41 d to which the signal pressure PS is input. In the presentembodiment, the oil is input to the first input port 41 a and the secondinput port 41 b through a second oil passage L2 that connects the firstswitching valve 41 and a second switching valve 42 described below. Theoil output from the output port 41 c is supplied to the hydraulic driveportion 70 side via a third oil passage L3. The signal pressure PS isinput to the signal pressure input port 41 d via the signal pressure oilpassage L8.

As illustrated in FIG. 5, the first switching valve 41 is configuredsuch that the first blocked state (the state in which the first inputport 41 a and the output port 41 c are blocked) is maintained(specifically, a biasing force of the spring for biasing the spool isadjusted) when the signal pressure PS is input to the signal pressureinput port 41 d, even when the oil is input to the second input port 41b from the first discharge port 31 a side. Further, as illustrated inFIG. 4, the first switching valve 41 is configured such that the firstblocked state is maintained even when the signal pressure PS is notinput to the signal pressure input port 41 d and the oil is not input tothe second input port 41 b from the first discharge port 31 a side.Thus, the state of the first switching valve 41 is switched to the firstblocked state during a state in which a failure is not occurring in thespecific state (the state shown in FIG. 5) or a state in which thesecond forward speed (Low) is formed (the state shown in FIG. 4).

In contrast, as illustrated in FIG. 6, the first switching valve 41 isconfigured such that the first allowing state (the state in which thefirst input port 41 a and the output port 41 c are in communication) ismaintained when the signal pressure PS is input to the signal pressureinput port 41 d and the oil is input to the second input port 41 b fromthe first discharge port 31 a side. If a failure occurs in the specificstate, the fourth control valve 54 is automatically non-energized or isnon-energized by being controlled by the control device 9, and thesignal pressure PS is not output to the signal pressure oil passage L8,that is, the signal pressure PS is not input to the signal pressureinput port 41 d. Thus, the state of the first switching valve 41 isswitched to the first allowing state when a failure occurs in thespecific state.

The hydraulic circuit 8 has the second switching valve 42 on an upstreamside of the first switching valve 41 in the oil passage connecting thefirst discharge port 31 a and the hydraulic drive portion 70. The secondswitching valve 42 is configured so as to be able to switch between asecond allowing state (the state shown in FIG. 5 and FIG. 6) in whichthe oil is allowed to flow from the first discharge port 31 a side tothe first switching valve 41 side and a second blocked state (the stateshown in FIG. 4) in which the flow of the oil from the first dischargeport 31 a side to the first switching valve 41 side is blocked.

Specifically, the second switching valve 42 is provided with an inputport 42 a to which the oil is input from the first discharge port 31 aside, an output port 42 b that outputs the oil to the first switchingvalve 41 side, a holding pressure input port 42 c to which the oiloutput to the first switching valve 41 side is input, a signal pressureinput port 42 d to which the signal pressure PS is input, and aswitching pressure input port 42 e to which hydraulic pressure suppliedto the third hydraulic drive portion 73 is input. In the presentembodiment, the oil is input to the input port 42 a via a first oilpassage L1 that is formed to branch from the first supply oil passageL11. The oil output from the output port 42 b is input to the holdingpressure input port 42 c, the first input port 41 a of the firstswitching valve 41, and the second input port 41 b of the firstswitching valve 41 via the second oil passage L2. The signal pressure PSis input to the signal pressure input port 42 d via the signal pressureoil passage L8. The oil is input to the switching pressure input port 42e via a fifth oil passage L5 formed to branch from the third control oilpassage L23.

As illustrated in FIG. 4, the second switching valve 42 is configuredsuch that the second blocked state (the state in which the input port 42a and the output port 42 b are blocked) is basically maintained when thesignal pressure PS is not input to the signal pressure input port 42 d.When the second forward speed (Low) or the reverse speed (Rev) isformed, the second hydraulic pump 32 is stopped. Thus, the signalpressure PS is not output to the signal pressure oil passage L8, thatis, the signal pressure PS is not input to the signal pressure inputport 42 d. Therefore, when the second forward speed (Low) or the reversespeed (Rev) is formed (the state shown in FIG. 4), the state of thesecond switching valve 42 is switched to the second blocked state.

In contrast, as illustrated in FIG. 5, the second switching valve 42 isconfigured such that the second allowing state (the state in which theinput port 42 a and the output port 42 b are in communication) ismaintained when the signal pressure PS is input to the signal pressureinput port 42 d. When forming the first forward speed (High), the fourthcontrol valve 54 is energized and the signal pressure PS is output tothe signal pressure oil passage L8. Thus, the state of the secondswitching valve 42 is switched to the second allowing state in thespecific state. As illustrated in FIG. 5, in the second allowing state,the hydraulic pressure output from the output port 42 b of the secondswitching valve 42 is input to the holding pressure input port 42 c as aholding pressure for holding a position of the spool of the secondswitching valve 42 (a holding pressure input state). The configurationis such that when the signal pressure PS is not input to the signalpressure input port 42 d in the holding pressure input state (see FIG.6), the state of the second switching valve 42 is maintained in thesecond allowing state by the holding pressure input to the holdingpressure input port 42 c. When a failure occurs in the specific state,the signal pressure PS is not output to the signal pressure oil passageL8, that is, the signal pressure PS is not input to the signal pressureinput port 42 d. Thus, in the present embodiment, when a failure occursin the specified state, the state of the second switching valve 42 ismaintained in the second allowing state by the hydraulic pressure(specifically, the hydraulic pressure supplied from the first dischargeport 31 a side to the holding pressure input port 42 c via the inputport 42 a and the output port 42 b) supplied to the second switchingvalve 42 from the first discharge port 31 a side.

As described above, when a failure occurs in the specific state, thestate of the first switching valve 41 is switched to the first allowingstate and the state of the second switching valve 42 is maintained inthe second allowing state. In this way, the configuration is such thatwhen a failure occurs in the specific state, the state of the hydrauliccircuit 8 is switched from the first supply state (the state shown inFIG. 5) to the second supply state (the state shown in FIG. 6). Althoughdetails are omitted, in the present embodiment, the control device 9 isconfigured to supply hydraulic pressure to the third hydraulic driveportion 73 when switching the shift speed from the first forward speed(High) to the second forward speed (Low) so as to engage the brake B.Thus, when performing control to switch the shift speed from the firstforward speed (High) to the second forward speed (Low), the state of thesecond switching valve 42 is switched to the second blocked state by thehydraulic pressure input to the switching pressure input port 42 e ofthe second switching valve 42. Also, since the state of the secondswitching valve 42 is switched to the second blocked state so that theoil of the second oil passage L2 is discharged from a drain port of thesecond switching valve 42, the state of the first switching valve 41 ismaintained in the first blocked state. In this way, the state of thehydraulic circuit 8 is not switched to the second supply state, and thesecond forward speed (Low) is formed.

As illustrated in FIG. 4, in present embodiment, the hydraulic circuit 8is provided with the second switching valve 42. Thus, when the secondforward speed (Low) or the reverse speed (Rev) is formed, the oil is notsupplied to the second oil passage L2. Thus, even when a failure occurswhen the second forward speed (Low) or the reverse speed (Rev) isformed, the state of the hydraulic circuit 8 is maintained in the stateshown in FIG. 4 and the state in which the second forward speed (Low) orthe reverse speed (Rev) is formed is maintained. That is, in the presentembodiment, the configuration is such that the state of the hydrauliccircuit 8 can be switched from the first supply state to the secondsupply state only when a failure occurs in the specific state.

As illustrated in FIG. 6, in the present embodiment, the configurationis such that in the second supply state, oil discharged from the firsthydraulic pump 31 is sequentially passed through the drain ports (51 c,52 c) and the output ports (51 b, 52 b) of the control valves (51, 52)to be supplied to the hydraulic drive portion 70. That is, in the secondsupply state, oil discharged by the first hydraulic pump 31 issequentially passed through the drain port 51 c and the output port 51 bof the first control valve 51 to be supplied to the first hydraulicdrive portion 71, and oil discharged by the first hydraulic pump 31 issequentially passed through the drain port 52 c and the output port 52 bof the second control valve 52 to be supplied to the second hydraulicdrive portion 72.

Specifically, as illustrated in FIG. 6, the first drain oil passage L31that is in communication with the drain port 51 c of the first controlvalve 51 is provided with a first check valve 61 that is switched from aclosed state to an open state in conjunction with the increase in thehydraulic pressure in the first drain oil passage L31 and that allowsthe oil to be discharged from the inside to the outside of the firstdrain oil passage L31. The first drain oil passage L31 is incommunication with an input port 61 a of the first check valve 61. Thus,when the oil supplied to the first hydraulic drive portion 71 isdischarged from the drain port 51 c of the first control valve 51, thefirst check valve 61 is switched to the open state by the hydraulicpressure supplied from the drain port 51 c to the input port 61 a of thefirst check valve 61 via the first drain oil passage L31 and thus, oildischarged from the drain port 51 c is discharged from the drain port 61c of the first check valve 61.

As described above, the oil output from the output port 41 c of thefirst switching valve 41 is supplied to the third oil passage L3. Asillustrated in FIG. 6, a fourth oil passage L4 is connected to the thirdoil passage L3, and a second check valve 62 that is switched from theclosed state to the open state in conjunction with the increase of thehydraulic pressure in the fourth oil passage L4 and that allows the oilto flow from the fourth oil passage L4 to the first drain oil passageL31 is provided in a connection portion of the fourth oil passage L4 andthe first drain oil passage L31. Thus, when the state of the firstswitching valve 41 is switched to the first allowing state due to theoccurrence of a failure in the specific state, the second check valve 62is switched to the open state by the hydraulic pressure that is suppliedfrom the output port 41 c of the first switching valve 41 to besequentially passed through the third oil passage L3 and the fourth oilpassage L4 to an input port 62 a of the second check valve 62 and thus,the oil output from the output port 41 c of the first switching valve 41is reverse input to the drain port 51 c of the first control valve 51via the first drain oil passage L31. The fourth oil passage L4 is alsoin communication with a back pressure input port 61 b of the first checkvalve 61. The first check valve 61 is maintained in the closed state bythe hydraulic pressure that is supplied from the output port 41 c of thefirst switching valve 41 to be sequentially passed through the third oilpassage L3 and the fourth oil passage L4 to the back pressure input port61 b of the first check valve 61. That is, in the second supply state,the first check valve 61 is maintained in the closed state by thehydraulic pressure supplied from the first discharge port 31 a side tothe first control valve 51.

When a failure occurs in the specific state, the first control valve 51is automatically non-energized or is non-energized by the control of thecontrol device 9 and thus, the drain port 51 c and the output port 51 bare in communication. In this way, in the second supply state, oildischarged from the first hydraulic pump 31 is sequentially passedthrough the drain port 51 c and the output port 51 b of the firstcontrol valve 51 to be supplied to the first hydraulic drive portion 71.

In contrast, as illustrated in FIG. 6, the second drain oil passage L32that is in communication with the drain port 52 c of the second controlvalve 52 is connected to the third oil passage L3. Then, the state ofthe first switching valve 41 is switched to the first blocked state (thestate shown in FIG. 5) while a failure is not occurring in the specificstate, and is set to the state in which the output port 41 c of thefirst switching valve 41 and the drain port of the first switching valve41 are in communication. Thus, when the hydraulic pressure supplied tothe second hydraulic drive portion 72 is discharged from the drain port52 c of the second control valve 52, oil discharged from the drain port52 c is sequentially passed through the second drain oil passage L32 andthe third oil passage L3 to be supplied to the first switching valve 41and is discharged from the drain port of the first switching valve 41.

In contrast, the state of the first switching valve 41 is switched tothe first allowing state (the state shown in FIG. 6) due to a failureoccurring in the specific state, the oil output from the output port 41c of the first switching valve 41 is reversely input to the drain port52 c of the second control valve 52 via the third oil passage L3 and thesecond drain oil passage L32. When a failure occurs in the specificstate, the signal pressure PS is not output to the signal pressure oilpassage L8, that is, the signal pressure PS is not input to the signalpressure input port 52 d of the second control valve 52. Thus, the stateof the second control valve 52 is switched to a state in whichcommunication between the input port 52 a and the output port 52 b isblocked and the output port 52 b and the drain port 52 c are incommunication. In this way, as illustrated in FIG. 6, in the secondsupply state, oil discharged from the first hydraulic pump 31 issequentially passed through the drain port 52 c and the output port 52 bof the second control valve 52 to be supplied to the second hydraulicdrive portion 72.

OTHER EMBODIMENTS

Next, other embodiments of the oil supply device and the vehicle drivetransmission device will be described.

(1) The configuration of the hydraulic circuit 8 shown in the aboveembodiment is an example, and the configuration of the hydraulic circuit8 can be changed appropriately. For example, in the embodiment describedabove, described as an example is the configuration in which in thesecond supply state, the first check valve 61 is maintained in theclosed state by the hydraulic pressure supplied from the first dischargeport 31 a side to the first control valve 51 (specifically, thehydraulic pressure supplied from the output port 41 c of the firstswitching valve 41 to the first control valve 51). However, withoutbeing limited to such a configuration, in the second supply state forexample, the first check valve 61 can be maintained in the closed stateby the oil supplied from a different output port of the first controlvalve 51 to the back pressure input port 61 b of the first check valve61.

In the embodiment described above, described as an example is theconfiguration in which in the second supply state, oil discharged fromthe first hydraulic pump 31 is sequentially passed through the drainports (51 c, 52 c) and the output ports (51 b, 52 b) of the controlvalves (51, 52) to be supplied to the hydraulic drive portion 70.However, without being limited to such a configuration, theconfiguration may be such that in the second supply state, oildischarged by the first hydraulic pump 31 is sequentially passed throughports other than the drain ports (51 c, 52 c) and the output ports (51b, 52 b) of the control valves (51, 52) to be supplied to the hydraulicdrive portion 70. Otherwise, the configuration may be such that in thesecond supply state, oil discharged by the first hydraulic pump 31 issupplied to the hydraulic drive portion 70 without interposing thecontrol valves (51, 52).

Further, in the embodiment described above, described as an example isthe configuration in which when a failure occurs in the specific state,the state of the second switching valve 42 is maintained in the secondallowing state by the hydraulic pressure supplied from the firstdischarge port 31 a side to the second switching valve 42 (specifically,the hydraulic pressure supplied from the first discharge port 31 a sideto be output from the output port 42 b of the second switching valve42). However, without being limited to such an configuration, theconfiguration may be such that when a failure occurs in the specificstate, the state of the second switching valve 42 is maintained in thesecond allowing state by the hydraulic pressure supplied from an outputport of a vale different from the second switching valve 42 to theholding pressure input port 42 c of the second switching valve 42.

Further, in the embodiment described above, described as an example isthe configuration in which the hydraulic circuit 8 has the secondswitching valve 42. However, without being limited to such aconfiguration, the configuration may be such that the hydraulic circuit8 is not provided with the second switching valve 42. In such a case,for example, when a failure occurs while the second forward speed (Low)is formed, the hydraulic circuit 8 may be structured so that the stateof the hydraulic circuit 8 may be switched to the second supply stateand the first forward speed (High) may be formed.

(2) The configuration of the transmission 6 shown in the aboveembodiment is an example. The transmission 6 having a differentconfiguration from that of the embodiment described above may be the oilsupply target of the oil supply device 7, if the transmission 6 isconfigured to form different shift speeds depending on whether hydraulicpressure is supplied to the specific engagement device D. For example,the transmission 6 configured as shown in FIG. 7 can be the oil supplytarget of the oil supply device 7. Similar to the transmission 6 of theembodiment described above, the transmission 6 shown in FIG. 7 is thetransmission 6 having the configuration in which the second forwardspeed having a speed ratio larger than that of the first forward speedis formed when the supply of the hydraulic pressure to the specificengagement device D is stopped in the state in which the first forwardspeed is formed. For example, the transmission 6 having theconfiguration in which a forward speed having a speed ratio smaller thanthat of the first forward speed is formed when supply of hydraulicpressure to the specific engagement device D is stopped in the state inwhich the first forward speed is formed, may be the oil supply target ofthe oil supply device 7.

In the example shown in FIG. 7, unlike the embodiment described above,the differential gear device 20 has the first rotating element E1, thesecond rotating element E2, the third rotating element E3, and a fourthrotating element E4 fixed to the case 4 by the first engagement deviceD1 in an engagement state, in the order of rotation speed. Specifically,the differential gear device 20 is configured by combining two planetarygear mechanisms (a third planetary gear mechanism 23 and a fourthplanetary gear mechanism 24). Of the three rotating elements eachprovided in the third planetary gear mechanism 23 and the fourthplanetary gear mechanism 24, the rotating elements are coupled two bytwo so as to rotate integrally with each other. In this way, thedifferential gear device 20 having four rotating elements as a whole isformed.

In the example shown in FIG. 7, as the third planetary gear mechanism23, a single pinion type planetary gear mechanism having a third sungear 23 s, a third carrier 23 c, and a third ring gear 23 r is used, andas the fourth planetary gear mechanism 24, a double pinion typeplanetary gear mechanism having a fourth sun gear 24 s, a fourth carrier24 c, and a fourth ring gear 24 r is used. The third sun gear 23 s is afirst rotating element E1, the third carrier 23 c and the fourth sungear 24 s that are coupled so as to rotate integrally with each otherare the second rotating element E2, the third ring gear 23 r and thefourth ring gear 24 r that are coupled so as to rotate integrally witheach other are the third rotating element E3, and the fourth carrier 24c is the fourth rotating element E4. The configuration may be such thatthe coupling relationship between the third planetary gear mechanism 23and the fourth planetary gear mechanism 24 is different from the exampleshown in FIG. 7. A configuration using a double pinion type planetarygear mechanism as the third planetary gear mechanism 23, a configurationusing a single pinion type planetary gear mechanism as the fourthplanetary gear mechanism 24, or a combination thereof are also possible.Further, the differential gear device 20 may be configured by aRavigneaux type planetary gear mechanism.

In the example shown in FIG. 7, the transmission 6 includes a firstbrake B1 corresponding to the brake B in the embodiment described above.In the transmission 6, unlike the embodiment described above, the firstengagement device D1 is a brake (second brake B2) that selectively fixesthe fourth rotating element E4 of the differential gear device 20 to thecase 4. Specifically, the first engagement device D1 is a normal opentype brake. In the example shown in FIG. 7, as shown in FIG. 8, therotation input to the first rotating element E1 from the rotatingelectrical machine 10 side is decelerated and output from the secondrotating element E2 to the output member 3 side, even when the firstforward speed (High) is formed in addition to when the second forwardspeed (Low) is formed.

(3) In the above embodiment, the second engagement device D2 has beendescribed as an example in which the second engagement device D2 is theone-way clutch F capable of switching between at least the one-directionrestriction state and the rotation restriction state. However, withoutbeing limited to such a configuration, it is also possible to use anormal closed type brake as the second engagement device D2. That is,the second engagement device D2 is switched to the released state by thehydraulic pressure being supplied to the second hydraulic drive portion72 and the second engagement device D2 can be switched to the engagementstate by the supply of the hydraulic pressure to the second hydraulicdrive portion 72 being stopped.

(4) In the embodiment described above, a configuration is described asan example in which the transmission 6 includes two specific engagementdevices D that are the first engagement device D1 and the secondengagement device D2, as the specific engagement device D to which thehydraulic pressure is supplied when forming the first forward speed.However, without being limited to such a configuration, the transmission6 may be configured to include only one specific engagement device D orthree or more specific engagement devices D.

(5) The configuration disclosed in the each embodiment described abovemay be applied in combination with the configuration disclosed in theother embodiments as long as no contradiction occurs (includingcombinations of the embodiments described above as the otherembodiments). Regarding the other configurations, the embodimentsdisclosed in the present specification are merely examples in allrespects. Thus, various modifications can be appropriately made withoutdeparting from the spirit of the present disclosure.

Summary of the Above Embodiment

Hereinafter, a summary of the oil supply device and the vehicle drivetransmission device described above will be described.

An oil supply device (7) that supplies oil to a transmission (6)provided in a power transmission path connecting a rotating electricalmachine (10) and wheels (2), and the transmission (6) is configured toform different shift speeds based on whether hydraulic pressure issupplied to a specific engagement device (D), the oil supply device (7)including: a first hydraulic pump (31) driven by power transmittedthrough the power transmission path; a second hydraulic pump (32) drivenby a driving force source (M2) independent from the power transmissionpath; a first supply oil passage (L11) that supplies oil discharged bythe first hydraulic pump (31) to a lubrication required part (30) of thetransmission (6); and a second supply oil passage (L12) that suppliesoil discharged by the second hydraulic pump (32) to a hydraulic driveportion (70) of the specific engagement device (D).

According to the configuration described above, oil discharged by thesecond hydraulic pump (32) driven by the driving force source (M2)independent from the power transmission path can be supplied to thehydraulic drive portion (70) of the specific engagement device (D) viathe second supply oil path (L12). Thus, by continuing to drive thesecond hydraulic pump (32) when the vehicle is caused to stop in thestate in which hydraulic pressure is supplied from the second hydraulicpump (32) to the specific engagement device (D) so that one shift speedis formed, it is possible to maintain the state in which the shift speedis formed until the vehicle is stopped.

According to the configuration described above, besides the secondhydraulic pump (32), the first hydraulic pump (31) driven by powertransmitted through the power transmission path is provided, and oildischarged by the first hydraulic pump (31) can be supplied to thelubrication required part (30) of the transmission (6) via the firstsupply oil passage (L11). Thus, compared to when oil discharged by thesecond hydraulic pump (32) is supplied to the lubrication required part(30) of the transmission (6), is possible to suppress the dischargecapacity required for the second hydraulic pump (32) (specifically, themaximum value of the required discharge amount) to be small. In thisway, the cost can be reduced and the efficiency can be improved. Interms of the first hydraulic pump (31), since oil discharged by thesecond hydraulic pump (32) can be supplied to the hydraulic driveportion (70) of the specific engagement device (D), the dischargecapacity required for the first hydraulic pump (31) (specifically, themaximum required discharge pressure) can be suppressed to be small. Inthis way, it is possible to reduce the energy loss that occurs inconjunction with the first hydraulic pump (31) being driven and improvethe efficiency.

As described above, according to the configuration described above, itis possible to reduce the cost and improve the efficiency when using thehydraulic pump (32) driven by the driving force source (M2) independentfrom the power transmission path. According to the configurationdescribed above, since the discharge capacities of both the firsthydraulic pump (31) and the second hydraulic pump (32) can be suppressedto be small, there is the advantage of being able to reduce the size ofthe two hydraulic pumps (31, 32).

Here, the transmission (6) is configured to form a first forward speedby supplying the hydraulic pressure to the specific engagement device(D) and a second forward speed having a larger speed ratio than that ofthe first forward speed when supply of the hydraulic pressure to thespecific engagement device (D) is stopped in a state in which the firstforward speed is formed.

When the transmission (6) is configured as described above, if thesecond hydraulic pump (32) is not provided, when the vehicle is causedto stop in the state in which the first forward speed is formed, it isnot possible to maintain the state in which the first forward speed isformed until the vehicle is stopped and there is a possibility that thevehicle behavior is changed in conjunction with the shift in speed fromthe first forward speed to the second forward speed. In this regard,since the present disclosure according to the oil supply device (7) hasthe second hydraulic pump (32), it is possible to maintain the state inwhich the first forward speed is formed until the vehicle is stopped,when the vehicle is caused to stop in the state in which the firstforward speed is formed.

A vehicle drive transmission device (1) includes: the oil supply device(7); the rotating electrical machine (10); the transmission (6); and anoutput member (3) that is drivingly coupled to the wheels (2). Thetransmission (6) includes a first engagement device (D1) and a secondengagement device (D2) that are the two specific engagement devices (D),and a differential gear device (20). The differential gear device (20)at least includes, in an order of rotational speed, a first rotatingelement (E1) that is drivingly coupled to the rotating electricalmachine (10), a second rotating element (E2) that is drivingly coupledto the output member (3), and a third rotating element (E3) that isselectively fixed to a non-rotating member by the second engagementdevice (D2). Two rotating elements of the first rotating element (E1),the second rotating element (E2), and the third rotating element (E3)are coupled by the first engagement device (D1) in an engagement stateor the differential gear device (20) includes the first rotating element(E1), the second rotating element (E2), the third rotating element (E3),and a fourth rotating element (E4) fixed to a non-rotating member (4) bythe first engagement device (D1) in the engagement state, in an order ofrotation speed. A reaction force torque that is applied to the thirdrotating element (E3) when the rotating electrical machine (10) outputsa normal rotation torque (T1) in a forward power running direction is afirst reaction force torque (TR1), and a reaction force torque that isapplied to the third rotating element (E3) when the rotating electricalmachine (10) outputs a reverse rotation torque (T2) that is in adirection opposite to the normal rotation torque (T1) is a secondreaction force torque (TR2). The second engagement device (D2) isconfigured so as to at least be able to be switched between aone-direction restriction state in which rotation of the third rotatingelement (E3) is restricted to one direction and a rotation restrictionstate in which rotation of the third rotating element (E3) is restrictedin both directions, and in the one-direction restriction state, thesecond engagement device (D2) restricts rotation of the third rotatingelement (E3) in a rotation direction caused by the first reaction forcetorque (TR1) and allows rotation of the third rotating element (E3)caused by the second reaction force torque (TR2). The first engagementdevice (D1) is switched to the engagement state by hydraulic pressurebeing supplied to a first hydraulic drive portion (71) that is thehydraulic drive portion (70) of the first engagement device (D1), andthe second engagement device (D2) is switched to the one-directionrestriction state by hydraulic pressure being supplied to a secondhydraulic drive portion (72) that is the hydraulic drive portion (70) ofthe second engagement device (D2).

In this configuration, the first forward speed is formed in thetransmission (6) in the state in which hydraulic pressure is supplied tothe first engagement device (D1) and the second engagement device (D2)that are the specific engagement device (D), and the second forwardspeed having a larger speed ratio than that of the first forward speedis formed in the transmission (6) in the state in which hydraulicpressure is not supplied to the first engagement device (D1) and thesecond engagement device (D2). Thus, as described above, if the secondhydraulic pump (32) is not provided, when the vehicle is caused to stopin the state in which the first forward speed is formed, it is notpossible to maintain the state in which the first forward speed isformed until the vehicle is stopped and there is a possibility that thevehicle behavior is changed in conjunction with the shift in speed fromthe first forward speed to the second forward speed. In this regard,since the present disclosure according to the oil supply device (7) hasthe second hydraulic pump (32), it is possible to maintain the state inwhich the first forward speed is formed until the vehicle is stopped,when the vehicle is caused to stop in the state in which the firstforward speed is formed.

The oil supply device and the vehicle drive transmission deviceaccording to the present disclosure may have at least one of the effectsdescribed above.

DESCRIPTION OF THE REFERENCE NUMERALS

-   -   1: Vehicle drive transmission device    -   2: Wheel    -   3: Output member    -   4: Case (non-rotating member)    -   6: Transmission    -   7: Oil supply device    -   10: Rotating electrical machine    -   20: Differential gear device    -   30: Lubrication target part (lubrication required part)    -   31: First hydraulic pump    -   32: Second hydraulic pump    -   70: Hydraulic drive portion    -   71: First hydraulic drive portion    -   72: Second hydraulic drive portion    -   D: Specific engagement device    -   D1: First engagement device    -   D2: Second engagement device    -   E1: First rotating element    -   E2: Second rotating element    -   E3: Third rotating element    -   E4: Fourth rotating element    -   L11: First supply oil passage    -   L12: Second supply oil passage    -   M2: Second driving force source    -   T1: Normal rotation torque    -   T2: Reverse torque    -   TR1: First reaction torque

1. An oil supply device that supplies oil to a transmission provided ina power transmission path connecting a rotating electrical machine andwheels, and the transmission is configured to form different shiftspeeds based on whether hydraulic pressure is supplied to a specificengagement device, the oil supply device comprising: a first hydraulicpump driven by power transmitted through the power transmission path; asecond hydraulic pump driven by a driving force source independent fromthe power transmission path; a first supply oil passage that suppliesoil discharged by the first hydraulic pump to a lubrication requiredpart of the transmission; and a second supply oil passage that suppliesoil discharged by the second hydraulic pump to a hydraulic drive portionof the specific engagement device.
 2. The oil supply device according toclaim 1, wherein the transmission is configured to form a first forwardspeed by supplying the hydraulic pressure to the specific engagementdevice and a second forward speed having a larger speed ratio than thatof the first forward speed when supply of the hydraulic pressure to thespecific engagement device is stopped in a state in which the firstforward speed is formed.
 3. A vehicle drive transmission devicecomprising: the oil supply device according to claim 1; the rotatingelectrical machine; the transmission; and an output member that isdrivingly coupled to the wheels, wherein the transmission includes afirst engagement device and a second engagement device that are the twospecific engagement devices, and a differential gear device, thedifferential gear device at least includes, in an order of rotationalspeed, a first rotating element that is drivingly coupled to therotating electrical machine, a second rotating element that is drivinglycoupled to the output member, and a third rotating element that isselectively fixed to a non-rotating member by the second engagementdevice, two rotating elements of the first rotating element, the secondrotating element, and the third rotating element are coupled by thefirst engagement device in an engagement state or the differential geardevice includes the first rotating element, the second rotating element,the third rotating element, and a fourth rotating element fixed to anon-rotating member by the first engagement device in the engagementstate, in an order of rotation speed, a reaction force torque that isapplied to the third rotating element when the rotating electricalmachine outputs a normal rotation torque in a forward power runningdirection is a first reaction force torque, and a reaction force torquethat is applied to the third rotating element when the rotatingelectrical machine outputs a reverse rotation torque in a directionopposite to the normal rotation torque is a second reaction forcetorque, the second engagement device is configured so as to at least beable to be switched between a one-direction restriction state in whichrotation of the third rotating element is restricted to one directionand a rotation restriction state in which rotation of the third rotatingelement is restricted in both directions, and in the one-directionrestriction state, the second engagement device restricts rotation ofthe third rotating element in a rotation direction caused by the firstreaction force torque and allows rotation of the third rotating elementcaused by the second reaction force torque, the first engagement deviceis switched to the engagement state by hydraulic pressure being suppliedto a first hydraulic drive portion that is the hydraulic drive portionof the first engagement device, and the second engagement device isswitched to the one-direction restriction state by hydraulic pressurebeing supplied to a second hydraulic drive portion that is the hydraulicdrive portion of the second engagement device.
 4. A vehicle drivetransmission device comprising: the oil supply device according to claim2; the rotating electrical machine; the transmission; and an outputmember that is drivingly coupled to the wheels, wherein the transmissionincludes a first engagement device and a second engagement device thatare the two specific engagement devices, and a differential gear device,the differential gear device at least includes, in an order ofrotational speed, a first rotating element that is drivingly coupled tothe rotating electrical machine, a second rotating element that isdrivingly coupled to the output member, and a third rotating elementthat is selectively fixed to a non-rotating member by the secondengagement device, two rotating elements of the first rotating element,the second rotating element, and the third rotating element are coupledby the first engagement device in an engagement state or thedifferential gear device includes the first rotating element, the secondrotating element, the third rotating element, and a fourth rotatingelement fixed to a non-rotating member by the first engagement device inthe engagement state, in an order of rotation speed, a reaction forcetorque that is applied to the third rotating element when the rotatingelectrical machine outputs a normal rotation torque in a forward powerrunning direction is a first reaction force torque, and a reaction forcetorque that is applied to the third rotating element when the rotatingelectrical machine outputs a reverse rotation torque in a directionopposite to the normal rotation torque is a second reaction forcetorque, the second engagement device is configured so as to at least beable to be switched between a one-direction restriction state in whichrotation of the third rotating element is restricted to one directionand a rotation restriction state in which rotation of the third rotatingelement is restricted in both directions, and in the one-directionrestriction state, the second engagement device restricts rotation ofthe third rotating element in a rotation direction caused by the firstreaction force torque and allows rotation of the third rotating elementcaused by the second reaction force torque, the first engagement deviceis switched to the engagement state by hydraulic pressure being suppliedto a first hydraulic drive portion that is the hydraulic drive portionof the first engagement device, and the second engagement device isswitched to the one-direction restriction state by hydraulic pressurebeing supplied to a second hydraulic drive portion that is the hydraulicdrive portion of the second engagement device.